Final answer:
The statement is true; heavy chain isotypes indeed have different functions, contributing to the diversity and specificity of antibody-mediated immune responses by defining the class or isotype of the antibody and dictating their role in immune defense mechanisms.
Step-by-step explanation:
The statement that heavy chain isotypes have different functions from one another is true. Antibodies, or immunoglobulins, are composed of two main types of polypeptide chains: light chains and heavy chains. Each antibody molecule consists of two identical heavy chains and two identical light chains. The heavy chains are responsible for defining the class or isotype of the antibody, with each class playing a distinct role in the immune response. The variable regions at one end of the antibody consist of parts of both the heavy and light chains and are important for the specificity of antigen binding. The function of the Fc region, which is formed by the two heavy chains, involves interactions with effector cells of the immune system through Fc receptors, facilitating activities such as pathogen neutralization and opsonization.